Apparatus for the examination of objects with ultra-sound, comprising an array of piezo-electric transducer elements
US4714846A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 1986 |
| Grant date | Dec 22, 1987 |
| Priority date | — |
| Expiry date | Oct 22, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0289
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for the examination of objects with ultrasound, comprising a linear or two-dimensional array (10) of piezo-electric transducer elements (10 (1), . . . , 10 (n)) with a length L and a width W, a stage for the repeated transmission of ultrasonic signals and a stage for the reception and processing of the ultrasonic echoes received. The thickness T of the elements is equal to half the wavelength corresponding to a first frequency F for which there exists, on the two-dimensional diagram of the curves F.multidot.T=f(W/T), or respectively, on the three-dimensional diagram of the curves F.multidot.T=f(W/T, L/T) of the distribution of the resonance frequencies, a first vibratory mode at the said first frequency F and a second vibratory mode at a second frequency equal to or near 2F. The transmission stage incorporates a generator (20) of excitation signals at the first frequency F, the spectrum of these excitation signals excluding at least the second frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.